necessary transferred to the system in order to remove the electrons to infinite distances apart from the nucleus and from each other is

equal to the total kinetic energy of the electrons.

We see that the only difference in the above formula and those holding for the motion of a single electron in a circular orbit round a nucleus is the exchange of

for

. It is also immediately seen that corresponding to the motion of an electron in an elliptical orbit round a nucleus, there will be a motion of the

electrons in which each rotates in an elliptical orbit with the nucleus in the focus, and the